Embodiments of the invention relate to an electrical junction box, and more particularly relate to an electrical junction box that can be used as both a watertight type and a nonwatertight type by attaching and detaching a rubber packing to the electrical junction box.
In the case where an electrical junction box connected to a wire harness is mounted on a motor vehicle inside an engine room or the like and is not exposed outside, the electrical junction box is generally of the nonwatertight type. On the other hand, in the case where an electrical junction box connected to a wire harness is mounted on a motor vehicle outside an engine room or the like and is exposed outside, the electrical junction box is generally of the watertight type.
In the watertight type electrical junction box, in order to prevent water from entering a clearance between a cover and a casing, the cover and casing must be interconnected through a sealing material. Consequently, there were some problems in the prior art. Specifically, a watertight type electrical junction box differs from a nonwatertight type electrical junction box with respect to structure. Additionally, the watertight type and nonwatertight type electrical junction boxes cannot have the same use, even if they have the same kind of function. Furthermore, costs of dies, the number of parts, and controlling steps are increased.
Thus, as shown in Patent Document 1 (JP 2004-877394), a containing box assembly for an electrical control device shown in FIGS. 10A and 10B is a watertight type junction box. The containing box assembly comprises an outer box 1 and a lid 2 for closing the outer box 1. The lid 2 is provided in a whole periphery on an opening end edge with a groove 2a that receives a seal material 3 for sealing the containing box assembly.
The sealing material 3 is pushed into the groove 2a to mechanically join the sealing material 3 to the lid 2. An upper opening end 1a of the outer box 1 is fitted in the groove 2a with the sealing material 3 being press-fitted in the groove 2a. By deforming the sealing material 3 so that the material 3 fills a clearance between the upper opening end 1a and the lid 2, a sealing function is kept for a long period in time in the containing box assembly for the electrical control device.
However, in the case where the containing box assembly for the electrical junction box is used as a nonwatertight electrical junction box, the sealing material 3 is not required. Consequently, a clearance between the groove 2a in the lid 2 and the upper opening end 1a is created where the sealing material 3 is no longer present. Accordingly, this clearance creates various problems. For example, the lid 2 on the outer box 1 rattles in the clearance and thereby generates noise during vehicle travel. Additionally, this rattling increases the probability of the lid 2 or the outer box 1 being damaged or broken during vehicle travel.
Therefore, the containing box assembly for the electrical control device disclosed in Patent Document 1 cannot effectively be used for both watertight and nonwatertight applications.